Juan Martin del Potro- One of my favorite players on tour, Juan Martin del Potro is best known for his fantastic win at the 2009 U.S. Open, becoming one of only two men to beat both Nadal and Federer in the same tournament. However, his momentum evaporated when a wrist injury forced him out of the game. Last year he came back and made a tremendous comeback to the top of the rankings, but fell short of the elite eight that qualify for the World Tour Final. This year, although he didn't make much noise at the slams, he raised his ranking to #7 and qualified for the World Tour Final. I believe this symbolizes the end of his comeback and the second beginning of his career at the top.
(The rest might be brief because nothing special really happened)
Jo-Wilfried Tsonga- One of, if not the most dynamic player in the top ten. He has an aggressive, great touch at the net, and plenty of power to spare. Not to mention he uses both a one-handed and two-handed backhand. Jo-Wilfried Tsonga definitely breaks the typical player mold of today. However, this year he has had decent results at best, his only tournament win coming from the Qatar open at the beginning of the year. He has hired a new coach, Rasheed, and displayed interesting tactics at the World Tour Final. Hopefully this new pairing will translate into success.
Janko Tipseravic- The other Serbian in the top ten, Janko Tipseravic has won three titles this year. He also managed to qualify for the World Tour Finals where he beat Ferrer and erased his chance of advancing to the semifinals.
Richard Gasquet- He's french.
Thank You everybody for reading and thank you to the OP for giving me something to kill time with on this boring day!